1. 阅读下列程序，写出运行结果，然后用Runnable接口编写程序来实现同样功能。class SimpleThread extends Thread{ public SimpleThread(String str){ super(str); } public void run(){ for (int i=0;i<10;i++){ System.out.println(i+" "+getName()); try{ sleep((int)(Math.random()*1000)); } catch (InterruptedException e){ } } System.out.println("DONE!"+getName()); } } public class TwoThreadsTest{ public static void main(String args[]){ new SimpleThread("First").start(); new SimpleThread("Second").start(); } }

上述程序的运行结果可能因为随机性而略有不同，但基本上应该是类似于这样：

0 First
0 Second
1 First
1 Second
2 First
2 Second
3 First
3 Second
4 First
4 Second
5 First
DONE!First
5 Second
6 Second
DONE!Second
6 First
7 First
7 Second
8 Second
8 First
9 Second
9 First
DONE!Second
DONE!First

以下是使用Runnable接口编写的程序：

class SimpleRunnable implements Runnable {
    private String name;

    public SimpleRunnable(String name) {
        this.name = name;
    }

    public void run() {
        for (int i = 0; i < 10; i++) {
            System.out.println(i + " " + name);
            try {
                Thread.sleep((int) (Math.random() * 1000));
            } catch (InterruptedException e) {
            }
        }
        System.out.println("DONE!" + name);
    }
}

public class TwoThreadsTest {
    public static void main(String[] args) {
        Thread t1 = new Thread(new SimpleRunnable("First"));
        Thread t2 = new Thread(new SimpleRunnable("Second"));
        t1.start();
        t2.start();
    }
}

这个程序与上述程序的功能相同，但使用了Runnable接口来实现多线程。注意，由于Runnable接口本身没有start()方法，因此我们需要创建一个Thread对象并将Runnable对象传递给它，然后调用Thread的start()方法来启动线程。